1. Technical Field
The present invention relates to liquid ejecting heads that eject liquid through nozzles, and more specifically to liquid ejecting heads in which liquid flow paths are formed by bonding a plurality of substrates to each other.
2. Related Art
Liquid ejecting heads that eject a liquid such as ink through nozzles are known. A liquid ejecting head includes piezoelectric elements that deform in response to the applied voltage, flow paths through which liquid flows and nozzles that communicate with the flow paths and allow the liquid to be ejected through the nozzles. Accordingly, when a pressure is generated in the flow paths due to deformation of the piezoelectric elements, the pressure causes the liquid flowing through the flow paths to be ejected through the nozzle openings. Such a liquid ejecting head is used, for example, as part of the printing apparatus or the like.
Further, liquid ejecting heads in which flow paths are formed by bonding a plurality of stacked substrates so that liquid flows through the flow paths. For example, the flow paths are formed by stacking a nozzle plate in which nozzles are formed, a flow path forming substrate having piezoelectric elements and pressure chambers in which a pressure is generated by the piezoelectric elements, and a communication plate in which communication holes are formed so as to communicate the nozzles and the pressure chambers with each other, and bonding the substrates by using an adhesive. The flow paths for the liquid are formed inside the bonded substrates.
When a plurality of substrates are bonded by using an adhesive to form the flow paths, the adhesive may flow out from between the substrates and the flowed out adhesive may cure inside the flow path. When the liquid ejecting head is actuated, the adhesive may be peeled off inside the flow path, leading to nozzle clogging. The nozzle clogging causes ejection failure of the liquid ejecting head. JP-A-2004-114556 discloses the prevention of ejection failure by cleaning the adhesive inside the flow path by using a solvent or the like.
It has been difficult to completely remove the adhesive inside the flow path when the adhesive is cleaned by using a solvent. Although it is possible to provide a form on the inner wall of the flow path in order to prevent the adhesive from creeping up on the wall, this requires precise designing of the form dimensions depending on the viscosity or applied amount of the adhesive. Such precise designing of dimensions may limit the design freedom of the flow path.